Synthesis, Crystallization, and Enzymatic Degradation of the Biodegradable Polyester Poly(ethylene azelate)

Poly(ethylene azelate) (PEAz) was synthesized and its melting behavior was studied with DSC and Step Scan DSC. The equilibrium melting point of PEAz was found 62 degrees C and the heat of fusion of 100% crystalline polymer was estimated at 160 J.g(-1). Polarized light microscopy showed mixed birefringence. From isothermal crystallization DSC study, after self-nucleation, crystallization rates were estimated. The Lauritzen-Hoffman plots showed crystallization regime I to II and II to III transition at 34 and 19 degrees C respectively. Non-isothermal crystallization was studied. The activation energy was calculated applying the isoconversional method of Friedman. Chemical hydrolysis of PEAz was very slow, while enzymatic hydrolysis showed comparable rates with PCL.